Valve operating mechanism



Jan. 3, 1939. J. D. TURLAY 2,142,224

VALVE OPERATING MECHANISM Filed Dec. 28, 1936 W70 v Y Z22 Patented Jan.3, 1939 PATENT OFFICE VALVE OPERATING MECHANISM Joseph D. Turlay, Flint,Mich assignor to Gen-' eral Motors Corporation, Detroit, Mich, acorporation of Delaware Application December 28, 1936, Serial No.117,797

9 Claims.

This invention relates to a valve operating mechanism for an internalcombustion engine and more particularly to a valve operating mechanismfor a valve of the poppet type in which two or more springs are used forclosing the valve.

It is an object of this invention to provide a valve operating mechanismof simple construction that is quiet in operation.

Another object of this invention is to provide a simple means foroperating a poppet valve of the type utilizing two or more springs inwhich noise andwear of parts are greatly reduced over other mechanismsheretofore used.

It is also an object of this invention to provide a means for operatinga poppet valve having more than one spring comprising a means whichenables the valve springs to be picked up successively.

A further object of this invention is to provide a means for operating apoppet valve having more than one spring, which reduces shock on themechanism in opening the valve against the valve spring preload overmechanisms heretofore used involving a. plural spring arrangement.

A still further object of this invention comprises a valve operatingmechanism in which rocker arm or lifter rattle just after the valve isseated in practically obviated.

Still another object of this invention is to provide a valve operatingmechanism for poppet valves having more than one spring, which greatlyreduces noise and wear of parts over other devices used in the pastwithout affecting the seating pressure of the valve and without puttinga spring load on the cam and lifter mechanism when the valve is closed.

Other advantages and objects of this invention will become more apparentas the description proceeds. Reference is herein made to the drawingforming a portion of this specification in which:

Figure 1 is a view with parts in section of a portion of an internalcombustion engine having a poppet valve and two valve springs forseating the valve against its seat, in which the mechanism of thisinvention is incorporated.

Figure 2 is a view generally similar to Figure l of a modification ofthe invention.

In Figures 1 and 3 of the drawing, 6 is a poppet valve having a valvestem 8. The valve is shown in seating engagement at [0 with a valve portI2 formed in a head member I3 of an internal combustion engine. A rockerarm 14, pivoted at IE to a valve rocker arm shaft I8, is adapted to beoperated by means of any suitable cam and push rod arrangement, notshown in the drawing. The rocker arm at timed intervals will open thevalve against the force of inner and outer springs 20 and 22,respectively. The valve stem 8 is slidablyfitted within a bushing 24mounted within an opening 26 in the head 13.

The upper or free end of the valve stem has two portions 28 and 30 ofreduced diameter. c-shaped washers 32 and 34 fitted around the valvestem at the reduced portions 28 and 30, respectively, act as stops orrestraining members for a washer 36 and 'a flanged member 38. Theflanged member 38 loosely surrounds the valve stem and is held incontact with the C-shaped washer 34 by the inner spring 20. Any movement applied to the stem while opening the valve I will compress orcontract spring 20. The washer 36 loosely surrounds the valve stem andis held in contact with the C-shaped washer 32 while the rocker arm isin its at rest position by means of the outer valve spring,

Resting on the upper surface of the washer 36 is a flanged member 44having a raised central portion 45 spaced at 48 from the free end of thevalve stem when the rocker arm is in inoperative position.

When the rocker arm is actuated by the cam and push rod'the end 48 ofthe rocker arm will contact the upper surface of the central portion 45of flanged member 44 and move the same with washer 36 against the ,endof the outer spring 22 and compress the same until the lower surface ofthe central portion 45 contacts the end of the valve stem.

The end 48 of the rocker arm-will continue to move downwardly and willthen move the valve to open the same against the combined pressure ofthe two springs. In closing the valve against its seat the valve andvalve stem will be moved upwardly by means of the energy stored up inthe two compressed springs. After the valve is seated the washer 36 andflanged member 44 will be moved upwardly until the washer 36 contactsthe C-shaped washer 32. Shock and wear on the mechanism will be reducedwithout reducing the seating pressure of the valve against its seat bymeans of the two stage pick up of the springs. A slight clearance 50 isprovided between the end 48 of the rocker arm and the upper surface Imember 38.

of the flanged member 44 when the rocker arm is at rest. By means ofthis provision, there will be no spring pressure on the rocker arm andits operating mechanism during inoperative periods of the rocker arm.Noise of the valve mechanism is greatly reduced by the two stage pickup. The outer spring will apply a pressure for a. short period of timeon the rocker arm after the valve has closed which will have a steadyingeffect on the mechanism and eliminate or greatly reduce rocker arm, orlifter, rattle at this time,

In Figure 2, a modification of the invention is disclosed. The device isgenerally similar to the construction shown in Figure 1, except that theC-shaped washer 34 of Figure 1, is omitted and a flanged member. 52substituted for the flanged The member 52 has a portion 54 surroundingthe valve stem which contacts the under surface of the C-shaped washer32. The remaining parts of the construction of Figure '2 are identicalwith those of Figure 1 and are indicated by similar reference numerals.

The operation of the construction of Figure 2 is as follows: The valverocker arm end 48 will first contact the upper surface of the flangedmember 44 and move it with the washer 36, against the pressure of theouter spring 22 until the lower surface of the central portion 45 of theflanged member 44 engages the upper surface of the end of the valvestem, whereupon the C-shaped washer 32 will thereafter cause the member52 to move downwardly and thus" ation of the rocker arm. Valve lifterrattle is eliminated or reduced as in the device of Figures 1 and 3.

Another embodiment of the invention is shown in Figure 4 of the drawing.The valve springs, the bushing, and head are similar to like parts inFigure 1 and are represented by the same reference characters. Aslightly different form of valve stem than that of Figure 1 is shown at60. The valve stem has a portion 62 of reduced diameter having athreaded end 64. A look washer 66 and nut 68 secures a bushing 10 havinga flanged portion 12 to the reduced portion of the valve stem. Above theflanged portion and loosely surrounding the upper portion of the bushingis a washer 14 which is held against the lock washer 66 in the at restposition of the rocker arm by means of the outer valve spring 22. Arocker arm '16 having a forked end .portion 18 is provided for operatingthe valve. The forked end portion I8 contacts the upper surface ofwasher 14 on either side of the nut 68 during operation of the valve andis spaced at from the upper surface of the washer during at rest periodsof the rocker arm. A small space or clearance 82 is provided between thelower surface of the washer I4 and the upper surface of the flangeportion 12 during the at rest period in the cycle of operation. I

In the operation of the device of Figure 4, the rocker arm will beactuated at timed periods and the forked end thereof will be moved tofirst reduce to zero the clearance 80, whereupon further movement willforce the washer 74 downwardly to compress the outer spring 22 until thewasher contacts the upper surface of the flange 12. The under surface ofthe flange contacts the upper end of the inner valve spring 20 and stillfurther movement of the rocker arm will open the valve and thus compressthe spring 20 and further compress the outer spring 22. As in the othermodifications of the invention, a two stage pick up is provided havingthe advantages pointed out.

While I have shown and described my invention in connection with a valveoperating mechanism of the valve-in-head type, I wish it to be expresslyunderstood that the device is not so limited and the invention may beused with any desired valve operating mechanism utilizing more than onespring.

It will likewise be understood that many changes and modifications maybe made in the constructions and arrangements of the several partswithout departing from the spirit of my invention and I do not wish tolimitthe patent granted thereon other than as necessitated by the priorart.

I claim:

1. In an internal combustion engine, a valve having a stem, two valvesprings, means to support one of said springs whereby one end thereofcan move with respect to the valve stem a small amount, a fixed stop onsaid valve stem for limiting movement of the spring end away from thevalve seat and means to mount the other spring for movement with thevalve stem.

2. In an internal combustion engine, a valve having a stem, an inner andan' outer spring therefor, means to mount the inner spring for movementwith the valve stem, means to support the outer of said springs wherebyone end thereof can move with respect to the valve stem 2. small amount,a fixed stop for limiting movement of said outer spring end away fromthe valve seat, and means to compressthe outer spring a small amount andthereafter move the valve stem against the combined pressure of the twosprings.

3. In an internal combustion engine, a valve having a stem, a seat forsaid valve, a plurality of valve springs surrounding said valve stemconstantly urging the valve toward its seat, means mounted for movementon said valve stem con tacting one of said valve springs, a stop memberfor limiting movement of said movable means .in a direction away fromsaid seat, means movable with the valve for contacting another of saidvalve springs and means for moving said first mentioned means withrespect to the valve stem and for thereafter moving the valve againstthe pressure exerted by the plurality of springs.

4. In an internal combustion engine, a valve having a stem, a seat forsaid valve, a plurality of valve springs surrounding said valve stem,- amovable washer around said valve stem contacting one of said valvesprings, means secured to said valve stem to limit movement of thewasher in a direction away from said seat, means movable with the valvecontacting another of said valve springs, and means to move the washerand spring contacted thereby with respect to the valve stem and forthereafter opening the valve against the pressure exerted by theplurality of springs.

5. In an internal combustion engine, a valve of springs surrounding saidstem, a movable washer around said valve stem contacting one of saidsprings, means secured to the valve stem to limit movement of the washerin a direction away from said seat, means secured to the valve stem formovement therewith contacting another of said valve springs, and meanscontacting said washer to move the same and spring contacted therebywith respect to the valve stem and for thereafter opening the valveagainst the combined spring pressure.

6. In an internal combustion engine, a valve having a stem, a seat forsaid valve, a plurality of valve springs surrounding said stem, amovable washer around said valve stem engaging one of said springs,means secured to the valve stem to limit movement of said washer in adirection away from said seat, means movable with the valve contactinganother of said valve springs, means spaced from the end of the valvestem contacting said washer, means for moving the last mentioned meansand washer against the pressure of the first mentioned spring until saidmeans contacts the end of the valve stem and for thereafter moving thevalve and stem against the pressure of the plurality of springs.

'7. In an internal combustion engine, a valve having a stem, a flangedmember secured to the free end of the valve stem, a valve springcontacting one side of said flange, a washer surrounding the valve stemand a portion of said flanged member, a stop member, a second valvespring contacting one face of said washer and biasing the same away fromthe opposite face of said flange and into contact with said stop duringa portion ofthe cycle of valve operation to provide a clearance betweenthe washer and flange, means for moving the washer into contact with theflange to compress the second mentioned valve spring and for thereaftermoving the washer and flanged member to open the valve against thespring pressure exerted by the two springs.

8. In an internal combustion engine, a valve member having a stem, twostop members secured near the free end of said stem, a washersurrounding the valve stem, a flanged member surrounding said valvestem, a spring surrounding said valve stem for biasing said flangedmember against one of said step members, a second spring surroundingsaidvalve stem for biasing said washer against the other of said stopmembers during a portion of the cycle of valve operation, and means formoving the washer with respect to the valve stem to compress the secondmentioned spring and for thereafter opening the valve against thepressure of the two valve springs.

9. In an internal combustion engine, a valve member having a stem, astop member secured to the valve stem near the free end thereof, aflanged member surrounding the valve stem, a washer around the valvestem and flanged memher, a first spring for biasing the flanged memberagainst the stop, a second spring surrounding the valve stem formaintaining the washer in con tact with said stop member during aportion of the cycle of valve operation, and means for moving the washeraway from said stop and for thereafter moving the flanged member andwasher against the combined pressure exerted by the two springs.

JOSEPH D. TURLAY.

